1. Field
The present invention relates to a vane pump device.
2. Description of Related Art
For example, in a vane pump disclosed in JP-A-2013-50067, discharge ports are respectively provided at two positions which face each other in a diameter direction passing through the center of a rotor, one of the two discharge ports is referred to as a main discharge port, and the other is referred to as a sub-discharge port. The main discharge port is connected to a discharge passage and a discharge outlet so as to normally supply discharged oil to a fluid device. The sub-discharge port communicates with the discharge passage and the discharge outlet via a communication passage.
JP-A-2011-196302 discloses a vane pump including a switching valve that switches between a full discharge position at which a working fluid is suctioned and discharged in both main and sub regions and a half-discharge position at which the working fluid is suctioned and discharged only in the main region. The switching valve switches the pressure of the working fluid introduced to vanes in the sub region such that the vanes retract to the rotor and move away from the inner circumferential cam surface of the cam ring at the half-discharge position.
Since separate passages for working fluids having different discharge pressures are required to be formed in a vane pump device that discharges a working fluid at multiple discharge pressures, the shape of the vane pump device is complex, and the volume of the vane pump device increases, which is a problem. A vane pump device desirably is compact from the point of view of saving in space of a vehicle in which the vane pump device is mounted, and of ensuring spaces of the vehicle in which components other than the vane pump device are disposed.